This invention relates generally to machines for the manufacture of building block and more particularly concerns machines for making blocks of pressed earth.
Presently known pressed earth block machines are deficient for several reasons. One problem is that the bucking block against which the earth is pressed is braced against a high friction device. This can result in severe weakening of the bucking block assembly as well as irregular geometry in the building blocks. Another problem is that known machines press the earth either until compression ceases or until the press stroke has traveled a fixed distance. Due to variations in the consistency of the earth being compacted, the former results in blocks of different depths while the latter result in blocks of different density. A third problem is that known press machines produce a relatively high percentage of damaged blocks because the compacted earth adheres to the surface of the press foot used to drive the earth against the bucking block, resulting in crumbling or disintegration of the finished block as it is pushed off the press foot.
It is, therefore, an object of this invention to provide a pressed earth block machine which makes pressed earth blocks of constant density and depth. Another object of this invention is to provide a pressed earth block machine which facilitates the rapid production of uniform earth blocks. Yet another object of this invention is to provide a pressed earth block machine which resists displacement of its bucking block during the pressing process. Similarly, it is an object of this invention to provide a pressed earth block machine having a device fixed against displacement in the direction of the pressing force and engageable with its bucking block during the pressing process. It is further an object of this invention to provide a pressed earth block machine having a bucking block anti-displacement device which is axially adjustable to maximize its effectiveness. Still another object of this invention is to provide a pressed earth block machine which is capable of producing uniform blocks regardless of variations in the composition of the earth being compressed. Similarly, it is an object of this invention to provide a pressed earth block machine having a sight-line assembly facilitating adjustment of the level of the machine press foot to compensate for variations in the compressibility of the earth. And it is an object of this invention to provide a pressed earth block machine having a press foot adapted to reduce the possibility of crumbling and disintegration of the pressed block during its removal from the press foot due to sticking or adhesion of the block to the press foot.